Axially expandable and contractable container



Jan. 7, 19% F. E. SLAWINSKI ETAL 3,

AXIALLY EXPANDABLE AND CONTRACTABLE CONTAINER Fi ed March 31, 1967 Sheet INVENTORS Frank E. Slowinski Herbert H. Whetstone MIRA FIG.

Jan. 7, 1969 F. E. SLAWINSKI ETAL 3,420,173

AXIALLY EXPANDABLE AND CONTRACTABLE] CONTAINER Sheet Filed March 31, 1967 INVENTORS Frank E. Slowinski Herbert H. Whetstone United States Patent 8 Claims Int. Cl. F42b 3/00; C06c 1/00 ABSTRACT OF THE DISCLOSURE A thin-walled container having bellows disposed along its length for axial expansion and contraction by contained materials which undergo variation in volume through physical or chemical changes. The container is particularly useful for containing explosives and for forming an explosive column assembly comprising a number of individual containers.

This invention relates to a new axially expandable and contractable container for materials which undergo variation in volume through either physical or chemical changes. More particularly, the present invention relates to a container having bellows disposed along its cylindrical length and which may be usefully employed to contain explosives in an explosive column assembly.

In the packaging, storing and handling of explosives, containers formed of various materials such as paper, metal and plastic have been employed along with various types of coupling means for forming an explosive column assembly. Paper containers have found wide acceptance for packaging explosives primarily because of inherent economic and safety factors. Paper containers, however, although widely accepted for versatility in packaging both cap sensitive and cap insensitive explosives require a considerable amount of water-proofing which increases wall thickness and insures a substantially rigid explosive container. Normally, paper packaged explosives are initiated by punching a hole through the side of the package and inserting a priming device such as a blasting cap. Once the paper package explosive is penetrated, damage resulting from water may result which limits the effectiveness of such explosives.

Metal containers have been widely accepted for their strength properties, Waterproofness and ease of coupling in forming an explosive column assembly. However, metal containers have been limited to packaging relatively insensitive explosives and are otherwise relatively expensive. Typically, metal containers are provided with a metal cap well into which is inserted an initiator such as a blasting cap. The metal cap well usually holds a blasting cap in such a manner that much of the effectiveness of the initiating force is lost.

Plastic containers have also been used for packaging explosives. These containers generally have standard configurations created for either paper or metal containers except for special construction features required in forming the plastic containers.

Containers employed in the explosive industry have included rigid containers such as those previously described and containers which may be referred to as radial- 1y expandable explosive packages. The latter type of package has employed the expandable feature as a means to completely fill a bore hole with a minimum of space between the expandable package or cartridge and the walls of a bore hole. Accordingly, once a package having the radially expandable feature is expanded by any means, it never returns to its original radial size. Further, the amount of pressure necessary to force the new radial size in such packages is greater than that normally internally available by the unexploded composition through variations in volume by physical or chemical changes. Otherwise, the container might radially expand during storage and become useless for its prescribed function.

It has now been found that by the practice of the present invention there is provided an axially expandable and contractable container for materials such as explosives which undergo variations in volume either through physical or chemical changes.

The present invention provides a thin-Walled container generally suitable for explosives and which includes bellows that expand and contract by changes of pressure within the container such as may be caused by physical or chemical changes. This invention further provides a standardized container for use in packaging a unit Weight of a series of explosive compositions which, depending upon the required function to be performed, may vary in volume by the addition of various proportions or additions of ingredients.

Generally stated, therefore, the present invention comprises a cylindrical container having bellows which axially expand and contract by internal volume changes of the contained material. The present invention also provides an explosive column assembly having a plurality of substantially cylindrical plastic containers charged with explosives and suitably connected to an initiating means.

The present invention will become more apparent from the following detailed description taken with regard to the accompanying drawings in which like numerals represent the same elements throughout the several views.

In the figures:

FIG. 1 is a side elevational view illustrating one embodiment of the container of the present invention;

FIG. 2 is a side elevational view illustrating the container of FIG. 1 except having auxiliary elements removed;

FIG. 3 is a top view of the container of FIG. 2;

FIG. 4 is bottom view of the container of FIG. 2;

FIG. 5 is an enlarged half section view taken as a partial side elevation illustrating a snap-cap useful for closing the mouth of the present container;

FIG. 6 is a side elevational view illustrating a second embodiment of the container of the present invention also having auxiliary elements removed;

FIG. 7 is a top view of the container of FIG. 6;

FIG. 8 is a bottom vieW of the container of FIG 6;

FIG. 9 is an enlarged half section view taken as a partial side elevation illustrating a snap-cap useful for closing the mouth of the embodiment container of FIG. 6; and

FIG. 10 is an enlarged half section view taken as a partial side elevation illustrating how the container of FIG. 6 may be connected to form an explosive column assembly.

Referring to FIG. 1, there is illustrated axially expandable container 10 having tubular sleeve 12 and container cap 14 as auxiliary elements therefor. The expandable container is desirably formed of a material which is compatible with explosive-type compositions and which, when provided with bellows 16 formed along the cylindrical length of the container, is axially expandable and contractable by materials contained therein which materials undergo significant volume changes through either physical or chemical changes. Bellows 16 illustrating as having a smaller diameter than the diameter of the body of container 10 is provided with a bottom containing surface 18 which may be either flat, concave, or convex.

Tubular sleeve 12 may be formed of flexible or rigid materials such as paper, plastic, or other suitable material which may be coated or uncoated and held in position about container 10 by flange 20 disposed near the bottom of the container and ridge 21 disposed near the top of the container. Alternately, sleeve 12 may be held in position by adhesive tape or other suitable adhesive means which may be applied at a construction site where the filled container is to be used. Cylindrical surface 22 between flange and ridge 21 defines the area generally covered by sleeve 12. The diameter of sleeve 12 is desirably limited to that diameter which will slip over yielding flange 20 and cylindrical surface 22 whereon the sleeve will be retained by flange 20 and ridge 21. Connected as an integral member to shoulder 24 is neck 26 having screw threads 28 to receive cap 14.

Disposed along cylindrical surface 22 is cap well 30 formed a an indention or channel along cylindrical surface 22 from a level originating to pass through flange 20. Thus, there is provided a convenient means through the area of flange 20 to pass lead-in wires from a cap positioned in cap well 30 through the channel cut through flange 20 when sleeve 12 is in position about cylindrical surface 22.

Disposed adjacent to cap well 30 is booster receiving groove 32 for receiving a booster explosive charge. Conveniently, booster receiving groove 32 is positioned along cylindrical surface 22 intermediate flange 20 and ridge 21 since no auxiliary fixtures such as lead-in wires are required for the booster explosive charge.

Disposed adjacent to booster-receiving groove 32 is detonator-receiving groove 34 for receiving a cord-like detonating means. The detonator-receiving groove 34 is axially disposed along the entire length of cylindrical surface 22 and through flange 20 at the lower end of container 10 and through ridge 21 and a portion of shoulder 24 at the upper end of container 10-.

Cap well 30, booster-receiving groove 32 and detonatorreceiving groove 34 may be formed as U-shaped grooves molded alongside of each other and generally parallel to the axis of the container. The depth of these grooves is generally that suflicient to receive the prescribed elements while permitting space for sleeve 12 to be fitted thereover.

FIG. 5 illustrates an enlarged half-section view taken as a partial side elevation which exemplifies snap-cap 36 useful for closing the mouth formed by neck 26 and defined by ring 38. Snap-cap 36 may be deep formed from a disc or may be formed or molded directly if desired. Snap-cap 36 includes circular base 40 having bowed surface 42 of slightly larger diameter than that of the internal diameter formed by ring 38 to provide a snap fit therewith. Bowed surface 42 is integral with concave surface 44 having an outer diameter about equal to the inner diameter of ring 38. In order to retain snapcap 36 in snug fit within ring 38, retaining wedge 46 as part of extended cap flange 48 is also included as an integral part of snap-cap 36.

In preparing an explosive column assembly with individual units of container 10, for example, when a noncap sensitive explosive is contained therein, a booster charge is held in booster-receiving groove 32 by sleeve 12. Disposed within each sleeve of an individual container may be positioned a cord-like detonator means which is suitably secured to the first of a series of these containers to be disposed along a length of the cord-like detonator means. In one of the series of containers forming the explosive column assembly, an explosive cap may be positioned in cap well 30. Ignition of the cap will thus ignite cord-like detonator and the booster. The booster will set off the explosive contained in an individual container while the cord-like detonator proceeds to set off boosters disposed in provided grooves on the remaining containers of the assembly.

Container 50 is illustrated in FIG. 6 as an embodiment container of the present invention. Container 50, which may have similar grooves to those provided for cap well 30, booster-receiving groove 32 and detonator-receiving groove 34, although not shown, is suitable for forming an explosive column assembly wherein individual containers are interconnected in head-to-toe relationship.

Container 50 includes toe ring 52 around bottom surface 54, and head ring 56 about upper neck 58 of the container. FIG. 6 illustrates container 50 as it may be received directly from a forming operation and includes plug 60 as an integral portion thereof. Thereafter, plug 60 may be severed along container top 62 and after the container is filled with material, plug 60 may be inserted into container top 62 as illustrated in FIG. 9. Plug 60 includes a mating concave surface 64 which usefully retains the plug in the concave shaped top side walls 66 of the container.

Bellows 68 are provided along the cylindrical surface of container 50 which function similarly to bellows 16 of FIG. 2. Although the bellows have been illustrated at either a protruding bottom portion of container 10 or along the cylindrical surface of container 50 of FIG. 6. it is recognized that the bellows may be disposed in any pattern along one end, both ends or at random intervals along the length of the container.

An explosive column assembly may be formed with container 50' by joining containers in head-to-toe relationship as illustrated in FIG. 10. Bottom surface 54 of container 50 mates with the outer surface of plug 60 as it is disposed in the container top 62 of the container.

The present container may be formed of any desirable thin-walled material which is compatible with explosivetype compositions and which, when provided with bellows formed along its cylindrical length is axially expandable and contractable by materials contained therein which materials undergo significant variations in volume through either physical or chemical changes. Thermoplastic materials are particularly useful for preparing the present containers since they generally possess favorable properties and may be economically blow-molded. Useful thermoplastic materials for preparing the present containers include materials such as polyvinyl resin, polyvinyl chloride, polystyrene, polyethylene, polypropylene, and cellulose and acrylic containing resins. Copolymers of these materials along with other materials such as plasticized vinyl chloride-vinyl acetate copolymers are also useful as are related terpolymers exemplified by acrylonitrile-butadiene styrene terpolymer.

Although the present containers are especially useful to contain explosives which experience significant variations in volume by either physical or chemical changes, they are also useful for containing non-explosives or otherwise unrelated materials which undergo significant variations in volume by either physical or chemical changes and which are customarily packaged for use in a column assembly comprising a number of individual containers. An example of a physical change is that of density which results by variation of temperature while an example of a chemical change is the generation of gas during storage by fermentation. Other well-known examples of such changes will become readily apparent to those skilled in the art.

A specific example of an explosive composition which may be contained in the present containers and which undergoes significant volume changes through either physical or chemical changes is the following:

Ingredient: Parts by weight Aqueous nitric acid solution (60%) Ammonium nitrate 400 Paraflin wax 5O Sorbitan monooleate 25 Copolymer of methyl vinyl ether-maleic anhydride 20 The plastic container of the present invention may be sealed to effect 'waterproofness if desired and is con structed such that there is no need for punching a hole in the container for priming. The contained material is thus in a neat, easy-to-handle container which may be assembled in the form of a column.

One of the advantages of the present container is that,

a unit weight of explosive composition may be packaged in a standardized volume container without need for concern of volume variations should such exist through varying the proportions or ingredients of the composition.

The cord-like detonating means for use with the present container may be a cord-like structure such as the wellknown Primacord or Cordeau. Other type structures or forms may also be used with modification if desired.

Commercial blasting caps which may be used with the present container are those which may contain primary explosives such as diazodinitrophenol, lead azide, mercury fulminate, either alone or combined with an oxygencarrying salt such as for example, potassium chlorate. These commercial blasting caps may also contain in conjunction with the primary explosives, secondary explosives such as tetryl, T.N.T., nitrostarch, P.E.T.N. or the like.

It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

1. A thin-walled container for explosive compositions which comprises, a container body portion containing an explosive composition and having expandable and contractable bellows formed as one end of the body portion whereby contained explosive materials may expand and contract without. any substantial varying in the radial configuration of the container.

2. The container of claim 1 wherein a plurality of U- shaped channels are disposed along the length of the body portion.

3. The container of claim 1 wherein said bellows has a diameter smaller than the diameter of said body portion.

4. The container of claim 1 wherein a sleeve is included to envelope a portion of said body portion.

5. The container of claim 1 wherein a snap-cap is included to close one end of the container body portion.

6. A plurality of containers of claim 2 containing an explosive composition and disposed along a length of cordlike detonating means to form an explosive column assembly, said cord-like detonating means being disposed in one of said U-shaped channels.

7. The container of claim 1 wherein said container is cylindrical shaped.

'8. The container of claim 1 formed of blow-molded plastic material.

References Cited UNITED STATES PATENTS 167,465 9/ 1875 Oliver 10224 542,041 7/ 1895 Butter-field et a1 1()224 1,220,208 3/1917 Ellis 10224 1,543,850 6/1925 Holderer 10224 1,988,091 1/1935 Shumacher 229-4.5 2,685,316 8/1954 Krasno. 2,887,953 5/1959 Mager 10 224 3,185,092. 5/ 1965 Hamilton 102-24 3,332,349 7/1967 Schwoyer et al. 10224 FOREIGN PATENTS 575,288 5/1959 Canada.

BENJAMIN A. BORCHELT, Primary Examiner.

V-ERLIN A. PENDEGRASS, Assistant Examiner. 

